1. Field of Invention
The embodiments of the invention relate in general to wireless communications, and more specifically to coordinating the use of radio resources by means of a set of operating parameters for efficient spectrum sharing between diverse wireless devices in unlicensed frequency bands.
2. Description of the Background Art
Radio frequency bands (i.e., spectrum) are both scarce and valuable, and therefore, efficient utilization of radio frequencies is essential. The usage of radio spectrum and regulation of radio emissions are coordinated by national regulatory bodies. These regulatory bodies attempt to coordinate the usage of radio frequency (RF) resources to achieve their most efficient usage and to avoid radio spectrum users causing interference towards each other.
The radio spectrum has been divided into two types of frequency bands—licensed and unlicensed. Licensed frequency bands are licensed out by the regulatory bodies to communication service providers and other users, for their exclusive usage. Further, a portion of the spectrum is reserved for defense and emergency applications. The small remaining part of the spectrum constitutes the unlicensed frequency bands.
Unlicensed frequency bands are a part of the radio spectrum, in which any type of radio service is permitted. For this reason, unlicensed frequency bands are also called spectrum commons. In contrast to a licensed approach, a diverse set of radio systems may operate on an unlicensed frequency band, using the same radio resources. As a result, available radio resources are used more frequently and at more places. This, in turn, leads to an increasing need to allocate a new unlicensed spectrum, and/or to provide the means to improve the utility of future unlicensed allocations. This requires spectrum-sharing between diverse radio systems with minimum interference.
There are two dimensions to spectrum sharing: vertical and horizontal sharing. Vertical sharing is between systems with different levels of regulating status, e.g., primary and secondary radio systems. Horizontal sharing is between systems with equal regulating status, e.g., between licensed users or between various types of unlicensed devices. Horizontal sharing can be further distinguished as single-species and multi-species sharing. Single-species sharing is the spectrum sharing between systems that are implemented, using the same technology or technology family. Multi-species sharing is spectrum sharing between technically different systems. Sophisticated and efficient solutions exist for single-species sharing. Exemplary solutions include standards such as Institute of Electrical and Electronics Engineers (IEEE) 802.11. However, the broader problem of a multi-species sharing is more complex, since the co-existing radio systems are assumed to be diverse. Therefore, exact behavior, such as based on IEEE 802.11, cannot be specified without restricting innovation.
A number of known spectrum-sharing techniques exist in current communication systems. However, all known spectrum-sharing techniques are very complex and impose constraints on the type of systems that can co-exist in the unlicensed spectrum. Further, regulations that are overly complex are difficult to understand and enforce. They also impose restrictions on new emerging technologies. Moreover, these techniques work by regulating specific parameters and therefore, they are not technology neutral and may exhibit reduced applicability and scalability.